According to Coulomb's Law, if the physical distance ($r$) between two stationary point charges is instantly doubled, the electrostatic force between them will:

The electric field intensity at a distance $r$ from a point charge $q$ is proportional to:

Electrical circuit problem 19: If a direct current of 2 Amperes flows through a resistor when a potential difference of 39 Volts is applied, what is its resistance?

Electrical circuit problem 18: If a direct current of 2 Amperes flows through a resistor when a potential difference of 38 Volts is applied, what is its resistance?

Electrical circuit problem 17: If a direct current of 2 Amperes flows through a resistor when a potential difference of 37 Volts is applied, what is its resistance?

Electrical circuit problem 16: If a direct current of 2 Amperes flows through a resistor when a potential difference of 36 Volts is applied, what is its resistance?

Electrical circuit problem 15: If a direct current of 2 Amperes flows through a resistor when a potential difference of 35 Volts is applied, what is its resistance?